The present invention relates to novel fungicidal compositions for the treatment of phytopathogenic diseases of crop plants, especially phytopathogenic fungi, and to a method of combating phytopathogenic diseases on crop plants.
It is known that certain substituted benzophenone derivatives have biological activity with high systemicity against phytopathogenic fungi, e.g. known from EP-A-897904, EP-A-899255 and EP-A-967196 where their properties and methods of preparation are described. On the other hand certain strobilurin derivatives, cyanoimidazole and carbonic acid amide compounds are known from the literature as plant fungicides for application in various crops of cultivated plants. However, crop tolerance and activity against phytopathogenic plant fungi of the known compounds do not always satisfy the needs of agricultural practice in many incidents and aspects.
It has now been found that the use of
a) a benzophenone of formula I 
wherein
R1 is methoxy, methyl, hydroxy, acetoxy or pivaloyloxy,
R2 is C1-C4alkoxy or 2-halogenbenzyloxy,
R3 is C1-C4alkoxy,
R4 is C1-C4alkyl, halogen or trifluoromethyl, and
R5 is hydrogen, halogen, C1-C4alkoxy, trifluoromethyl or nitro; in association with
b) the strobilurin of formula II 
is particularly effective in combating or preventing fungal diseases of crop plants. These combinations exhibit synergistic fungicidal activity.
The compounds of formula I are known from EP-A-897904, EP-A-899255 and EP-A-967196. Specific examples of preferred individual compounds are listed in the following table.
The chemical designation of the above listed compounds is as follows:
1.01 5-bromo-6,6xe2x80x2-dimethyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.02 5-chloro-6,6xe2x80x2-dimethyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.03 5-chloro-6,6xe2x80x2-dimethyl-3xe2x80x2-ethoxy-2,2xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.04 5-chloro-6,6xe2x80x2-dimethyl-3xe2x80x2-propoxy-2,2xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.05 5-trifluoromethyl-6,6xe2x80x2-dimethyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.06 6-chloro-6xe2x80x2-methyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.07 6-trifluoromethyl-6xe2x80x2-methyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.08 6,6xe2x80x2-dimethyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.09 5-bromo-6-chloro-6xe2x80x2-methyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.10 6-chloro-5,6xe2x80x2-dimethyl-2,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.11 5-chloro-2,6,6xe2x80x2-trimethyl-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.12 5-bromo-2,6,6xe2x80x2-trimethyl-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.13 5-nitro-2,6,6xe2x80x2-trimethyl-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.14 2,6,6xe2x80x2-trimethyl-5,2xe2x80x2,3xe2x80x2,4xe2x80x2-tetramethoxy-benzophenone,
1.15 5-chloro-2,6,6xe2x80x2-trimethyl-2xe2x80x2-butoxy-3xe2x80x2,4xe2x80x2-dimethoxy-benzophenone,
1.16 5-bromo-2,6,6xe2x80x2-trimethyl-2xe2x80x2-butoxy-3xe2x80x2,4xe2x80x2-dimethoxy-benzophenone,
1.17 5-nitro-2,6,6xe2x80x2-trimethyl-2xe2x80x2-butoxy-3xe2x80x2,4xe2x80x2-dimethoxy-benzophenone,
1.18 2,6,6xe2x80x2-trimethyl-2xe2x80x2-butoxy-5,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.19 5-chloro-2,6,6xe2x80x2-trimethyl-2xe2x80x2-(o-fluorobenzyloxy)-3xe2x80x2,4xe2x80x2-dimethoxy-benzophenone,
1.20 5-bromo-2,6,6xe2x80x2-trimethyl-2xe2x80x2-(o-fluorobenzyloxy)-3xe2x80x2,4xe2x80x2-dimethoxy-benzophenone,
1.21 5-nitro-2,6,6xe2x80x2-trimethyl-2xe2x80x2-(o-fluorobenzyloxy)-3xe2x80x2,4xe2x80x2-dimethoxy-benzophenone,
1.22 2,6,6xe2x80x2-trimethyl-2xe2x80x2-(o-fluorobenzyloxy)-5,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.23 6,6xe2x80x2-dimethyl-2-hydroxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.24 6,6xe2x80x2-dimethyl-2-acetoxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.25 5-bromo-6,6xe2x80x2-dimethyl-2-hydroxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.26 5-bromo-6,6xe2x80x2-dimethyl-2-acetoxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.27 5-chloro-6,6xe2x80x2-dimethyl-2-hydroxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone,
1.28 5-chloro-6,6xe2x80x2-dimethyl-2-acetoxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone, and
1.29 5-bromo-6,6xe2x80x2-dimethyl-2-pivaloyloxy-2xe2x80x2,3xe2x80x2,4xe2x80x2-trimethoxy-benzophenone.
The compound of formula II is known from the literature under common name azoxystrobin, code ICIA5504, e.g. from EP-A-382375.
Among these mixtures those are preferred in which the compound of formula I is one of the compounds 1.01, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.25, 1.26 or 1.27.
Throughout this document the expression combination stands for the various combinations of components a) and b), e.g. in a single xe2x80x9cready-mixxe2x80x9d form, in a combined spray mixture composed from separate formulations of the single active ingredient components, e.g. a xe2x80x9ctank-mixxe2x80x9d, and in a combined use of the single active ingredients when applied in a sequential manner, i.e. one after the other with a reasonably short period, e.g. a few hours or days. The order of applying the components a) and b) is not essential for working the present invention.
The combinations according to the invention may also comprise more than one of the active components a), if broadening of the spectrum of disease control is desired. For instance, it may be advantageous in the agricultural practice to combine two or three components a) with the compound of formula II.
The active ingredient combinations are effective against phytopathogenic fungi belonging to the following classes: Ascomycetes (e.g. Venturia, Podosphaera, Erysiphe, Monilinia, Mycosphaerella, Uncinula); Basidiomycetes (e.g. the genus Hemileia, Rhizoctonia, Puccinia); Fungi imperfecti (e.g. Botrytis, Helminthosporium, Rhynchosporium, Fusarium, Septoria, Cercospora, Alternaria, Pyricularia and Pseudocercosporella herpotrichoides); Oomycetes (e.g. Phytophthora, Peronospora, Bremia, Pythium, Plasmopara).
Target crops for the areas of indication disclosed herein comprise within the scope of this invention e.g. the following species of plants: cereals (wheat, barley, rye, oats, rice, sorghum and related crops); beet (sugar beet and fodder beet); pomes, stone fruit and soft fruit (apples, pears, plums, peaches, almonds, cherries, strawberries, raspberries and black-berries); leguminous plants (beans, lentils, peas, soybeans); oil plants (rape, mustard, poppy, olives, sunflowers, coconut, castor oil plants, cocoa beans, groundnuts); cucumber plants (marrows, cucumbers, melons); fibre plants (cotton, flax, hemp, jute); citrus fruit (oranges, lemons, grapefruit, mandarins); vegetables (spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, paprika); lauraceae (avocados, cinnamon, camphor); or plants such as maize, tobacco, nuts, coffee, sugar cane, tea, vines, hops, turf, bananas and natural rubber plants, as well as ornamentals (flowers, shrubs, broad-leaved trees and evergreens, such as conifers). This list does not represent any limitation.
The combinations of the present invention may also be used in the area of protecting technical material against attack of fungi. Technical areas include wood, paper, leather, constructions, cooling and heating systems, ventilation and air conditioning systems, and the like. The combinations according the present invention can prevent the disadvantageous effects such as decay, discoloration or mold.
The combinations according to the present invention are particularly effective against powdery mildews and rusts, pyrenophora, rhynchosporium, tapesia, fusarium and leptosphaeria fungi, in particular against pathogens of monocotyledonous plants such as cereals, including wheat and barley. They are furthermore particularly effective against downy mildew species, powdery mildews, leaf spot diseases and rusts in dicotyledonous plants.
The amount of combination of the invention to be applied, will depend on various factors such as the compound employed, the subject of the treatment (plant, soil, seed), the type of treatment (e.g. spraying, dusting, seed dressing), the purpose of the treatment (prophylactic or therapeutic), the type of fungi to be treated and the application time.
It has been found that the use of compounds of formula II in combination with the compound of formula I surprisingly and substantially enhance the effectiveness of the latter against fungi, and vice versa. Additionally, the method of the invention is effective against a wider spectrum of such fungi that can be combated with the active ingredients of this method, when used solely.
The weight ratio of a):b) is so selected as to give a synergistic fungicidal action. In general the weight ratio of a):b) is between 200:1 and 1:40. The synergistic action of the composition is apparent from the fact that the fungicidal action of the composition of a)+b) is greater than the sum of the fungicidal actions of a) and b).
The method of the invention comprises applying to the treated plants or the locus thereof in admixture or separately, a fungicidally effective aggregate amount of a compound of formula I and a compound of component b).
The term locus as used herein is intended to embrace the fields on which the treated crop plants are growing, or where the seeds of cultivated plants are sown, or the place where the seed will be placed into the soil. The term seed is intended to embrace plant propagating material such as cuttings, seedlings, seeds, germinated or soaked seeds.
The novel combinations are extremely effective on a broad spectrum of phytopathogenic fungi. Some of them have a systemic action and can be used as foliar and soil fungicides and for seed dressing.
The fungicidal combinations are of particular interest for controlling a large number of fungi in various crops or their seeds, especially wheat, rye, barley, oats, rice, maize, lawns, cotton, soybeans, coffee, sugarcane, fruit and ornamentals in horticulture and viticulture, in vegetables such as cucumbers, beans and cucurbits, and in field crops such as potatoes, peanuts, tobacco and sugarbeets.
The combinations are applied by treating the fungi or the seeds, plants or materials threatened by fungus attack, or the soil with a fungicidally effective amount of the active ingredients.
The agents may be applied before or after infection of the materials, plants or seeds by the fungi.
The novel combinations are particularly useful for controlling the following plant diseases:
Erysiphe graminis in cereals,
Erysiphe cichoracearum and Sphaerotheca fuliginea in cucurbits,
Podosphaera leucotricha in apples,
Uncinula necator in vines,
Puccinia species in cereals,
Rhizoctonia species in cotton, potatoes, rice and lawns,
Ustilago species in cereals and sugarcane,
Venturia inaequalis (scab) in apples,
Helminthosporium species in cereals,
Septoria nodorum in wheat,
Septoria tritici in wheat,
Rhynchosporium secalis on barley,
Botrytis cinerea (gray mold) in strawberries, tomatoes and grapes,
Cercospora arachidicola in groundnuts,
Peronospora tabacina in tobacco, or other Peronospora in various crops,
Pseudocercosporella herpotrichoides in wheat and barley,
Pyrenophera teres in barley,
Pyricularia oryzae in rice,
Phytophthora infestans in potatoes and tomatoes,
Fusarium and Verticillium species in various plants,
Plasmopara viticola in grapes,
Alternaria species in fruit and vegetables,
Pseudoperonospora cubensis in cucumbers,
Mycosphaerella fijiensis in banana,
Colleotrichum species in various crops.
When applied to the plants the compounds of formula I are applied at a rate of 20 to 2000 g/ha, particularly 20 to 1000 g/ha, e.g. 20, 30, 40, 75, 80, 100, 125, 150, 175, 200, 300, 500, 750, 1000, 1200, 1500 or 2000 g/ha, in association with 10 to 750 g/ha, particularly 20 to 1000 g/ha, e.g. 12.5 g/ha, 15 g/ha, 30 g/ha, 40 g/ha, 60 g/ha, 75 g/ha, 80/ha, 100 g/ha, 125 g/ha, 150 g/ha, 175 g/ha, 200 g/ha, 250 g/ha, 300 g/ha, 500 g/ha, 600 g/ha or 750 g/ha of the compound of formula II.
In agricultural practice the application rates of the combination depend on the type of effect desired, and range from 0.02 to 3 kg of active ingredient per hectare.
When the active ingredients are used for treating seed, rates of 0.001 to 50 g a.i. per kg, and preferably from 0.01 to 10 g per kg of seed are generally sufficient.
The invention also provides fungicidal compositions comprising a compound of formula I and the compound of formula II.
The composition of the invention may be employed in any conventional form, for example in the form of a twin pack, an instant granulate, a flowable formulation, an emulsion concentrate or a wettable powder in combination with agriculturally acceptable adjuvants. Such compositions may be produced in conventional manner, e.g. by mixing the active ingredients with appropriate adjuvants (diluents or solvents and optionally other formulating ingredients such as surfactants). Also conventional slow release formulations may be employed where long lasting efficacy is intended.
Particularly formulations to be applied in spraying forms such as water dispersible concentrates or wettable powders may contain surfactants such as wetting and dispersing agents, e.g. the condensation product of formaldehyde with naphthalene sulphonate, an alkylarylsulphonate, a lignin sulphonate, a fatty alkyl sulphate, and ethoxylated alkylphenol and an ethoxylated fatty alcohol.
A seed dressing formulation is applied in a manner known per se to the seeds employing the combination of the invention and a diluent in suitable seed dressing formulation form, e.g. as an aqueous suspension or in a dry powder form having good adherence to the seeds. Such seed dressing formulations are known in the art. Seed dressing formulations may contain the single active ingredients or the combination of active ingredients in encapsulated form, e.g. as slow release capsules or microcapsules.
In general, the formulations include from 0.01 to 90% by weight of active agent, from 0 to 20% agriculturally acceptable surfactant and 10 to 99.99% solid or liquid adjuvant(s), the active agent consisting of at least a compound of formula I together with the compound of formula II, and optionally other active agents, particularly microbides or conservatives or the like. Concentrated forms of compositions generally contain in between about 2 and 80%, preferably between about 5 and 70% by weight of active agent. Application forms of formulation may for example contain from 0.01 to 20% by weight, preferably from 0.01 to 5% by weight of active agent. Whereas commercial products will preferably be formulated as concentrates, the end user will normally employ dilute formulations.